No. I used vim for half a year and then went back to notepad++ and similar for plain editing. The bottleneck in programming is thinking anyway, and not typing. It does not make a difference. For serious coding, I recommend a serious IDE.
Any that don't suck at windowing? They all want to show only one, or at best two files at a time. They're primitive compared to the windowing capabilities of vim/emacs/tmux.
No, not really... prior to 2017, that was one of my biggest gripes with Visual Studio - opening multiple editor windows in one instance would quickly chew up enough memory to hit the 32-bit process limit and start page thrashing. Why, I have no idea, but that's what I've seen consistently the past few years in VS 2013 & 2015.
Does it do better now? Can you have 12 windows arranged at once? If so, please tell me how because I spend most of my day in VS. but time and time again I need to open shit in vim, just to get a clear overview.
Far as i know, no. I was settling for having 2-3 editor windows open at once. 2015 was such a pig I avoided it. 2017 can handle it so far. I wouldn't bet on big solutions 100k+ lines of code though.